1. Field of the Invention
The present invention relates to a system and method for wireless vehicle tire pressure monitoring that provide for automatic recognition of tire location.
2. Background
It is known in the automotive industry to provide for wireless monitoring of vehicle tire parameters, particularly tire pressure. In such tire pressure monitoring systems, tire pressure sensors and radio frequency (RF) transmitters are mounted inside each tire, typically adjacent the inflation valve stem. In each tire, the tire pressure sensed by the tire pressure sensor is transmitted by the transmitter to a receiver/controller located on the vehicle. The tire pressure information delivered to the receiver/controller by the RF signals from the transmitters is subsequently conveyed to a vehicle operator or occupant, typically in the form of a display.
Exemplary tire pressure monitoring systems are described and shown in U.S. Pat. Nos. 6,112,587 and 6,034,597. To recognize the particular tire location (e.g., front left (FL), front right (FR), rear left (RL), rear right (RR)) associated with an RF signal received from a tire transmitter, such tire pressure monitoring systems are programmed in an initialization or sign-up operation. That is, in order to provide a vehicle operator with information specific to each vehicle tire, programming of the tire pressure monitoring system must be undertaken by a technician or vehicle owner so that each RF signal from a tire transmitter will be associated with a particular tire location.
Current tire pressure monitoring systems use a magnetic reed switch in each tire for such programming. More particularly, after the on-board vehicle/controller is placed into a program, initialization, or sign-up mode, the magnetic reed switch in each tire is activated by a technician or vehicle owner using a magnet. Such activation causes the tire transmitter in the tire to transmit a tire pressure signal to the controller the vehicle. In that regard, each pressure sensor and/or transmitter has a unique identification code associated therewith, which identification code is transmitted with the tire pressure signal. Using such identification codes, and by following a preselected sequence for activating each magnetic reed switch, the controller associates each tire pressure signal with a particular tire location.
Such operation, however, can create problems when tires are subsequently rotated or changed from their initial locations to new locations, or a vehicle tire is replaced. Each time the vehicle tires are rotated or a tire is replaced, initialization or sign-up must be repeated to ensure that the system continues to operate properly by conveying accurate information, including tire location, to the vehicle operator. This initialization requirement makes tire rotation more complex, and increases the possibility of inaccurate operation of the system. Moreover, in the event the magnet for activating the reed switches is misplaced or lost, the tire pressure monitoring system cannot be properly programmed after tire rotation.
Thus, there exists a need for an improved system and method for identifying tire locations in a tire pressure monitoring system. Such a system and method would automatically recognizes tire location even after tire rotation or replacement, without the need for subsequent initialization or sign-up operations. Such a system and method would also do so easily and simply, without adding significant costs to the tire pressure monitoring system.
Accordingly, the present invention provides an improved system and method for vehicle tire pressure monitoring that provide for automatic recognition of tire location.
According to the present invention, then, in a system for remote monitoring of tire pressure in a vehicle having front tires comprising a right tire and a left tire, and rear tires comprising a right tire and a left tire, a system is provided for automatically identifying tire location. The system comprises a plurality of transmitters, each transmitter for mounting in one of the tires, each transmitter for transmitting tire information signals conveying tire pressure data and tire rotation direction data associated therewith. The system further comprises a receiver for receiving the tire information signals transmitted by the transmitters, the receiver for mounting on the vehicle at a location having a first distance from the front tires and a second distance from the rear tires, the first distance different from the second distance. The system still further comprises a controller for mounting on the vehicle and to be provided in communication with the receiver, the controller for determining whether pressure data conveyed by a tire information signal is associated with a front tire or a rear tire based on a strength of the signal, and for determining whether pressure data conveyed by a tire information signal is associated with a right tire or a left tire based on the associated rotation direction data.
Also according to the present invention, in a system for remote monitoring of tire pressure in a vehicle having front tires comprising a right tire and a left tire, and rear tires comprising a right tire and a left tire, a method is provided for automatically identifying tire location. The method comprises transmitting from each tire pressure data and rotation direction data associated therewith, and receiving at a selected location on the vehicle the pressure data and rotation direction data. The method further comprises determining whether pressure data is associated with a front tire or a rear tire based on a strength of a signal conveying the pressure data, and determining whether pressure data is associated with a right tire or a left tire based on the associated rotation direction data.
These and other features and advantages of the present invention will be readily apparent upon consideration of the following detailed description of the invention in conjunction with the accompanying drawings.